Concrete-drill.



F. L STEINBAH.

CONCRETE BRILL.

APPLICATION FILED M117, 1911.

Easented May 6, w13.

6 @QQ/M5@ adapted to transmit verticalreciprocatory motion to-a rod '29 mounted in bearings 304 which project laterally from the main cylinder 1. The connect-ion of the rod 29 'with 4the eccentric groove 28 consists in a friction roller 31 mounted on a stud 32 formed integral -or secured rigidly to said rod. The roller 31 thus travels in the groove 28 and causes a single depression of the rod 29 duringa complete, revolution of the gear 13. The vertical reciprocatory motion of the rod 29 is transmitted to a ratchet wheel 32 by means of a pivoted `gravity-operated 5 pawl 33 provided at the lower end of said rod, this action being clear by reference to Fig. 1. During a single downward stroke of the rod 29 the ratchet wheelA 32 is moved a circumferential distance corresponding 'with the width of4 one or two of the teeth thereof, thus producing an intermittent motion. Formed integral with the ratchet wheel 32 and disposed on thel inner side thereof vis a bevel lgear 34, said gear and ratchet wheel being rotatably mounted on-A a stationary laterally extending stud 35 formed integral with the cylinder extension 18. A cotter-pin36 retains the ratchet wheel and bevel gear in position. Meshing with the bevel gear 34 and driven thereby is a bevel gear 37 arranged coaxially with the cylinder extension 18 and adapted to rotate on the lower end thereof. The bevel gear 37 is held in position with reference to the cylinder extension 18 by means of two semicircular bands 38 which are secured to the periphery of the lower end of the cylinder extension 18 by means of screws 39 and are provided with inwardly extending flanges 40 for .engagementfwith a peripheral groove 41. provided at the upper end of the bevel gear 37. From this construction themanner of mounting and operation of the bevel gear 37 is apparent. In order to transmit motion to the tool holder 19 for feeding the drill 21 akey 42 is provided in the bore 43 l manner thel drill 21 is intermittently ro,

of the gear 37`which key projects into a longitudinal groove 44- formed in said toolholder, thus producing a splined connection of thev latter with said bevel gear. In this tatedV during the vertical reciprocations thereof.

After a vhole has been partially drilled,

;A drillings and dust ordinarily accumulate therein and to.prevent-suchl accumulation the followingl pneumatic means is provided:

This means comprime a, checkvalve 45. ar-

ranged in communication vwith the space in which. the plunger 6 operates, said bheckvalve being gravity-operated and permitting of free entrance of air to`said space4 when a partial vacuum is'formed therein '0 an outlet check-valve I46 arranged opposite the check-valve 45 and thence 'through a conduit 47 which discharges -in a region adjacent Vthe hole being drilled. The effect of the action as described is to clean the hole being drilled from all dust and accumulation of any kind The mode of the. operation of the drill is as follows: The handle 3. of the device is held in one hand and the handle `16 rotated. with the other,`the drill 21 being properly positioned on the rock or concret-e to be drilled. Then the handle-16 is rapidly turned which causes the drill 21 to reciprocate vertically in a rapid manner and 'to turn slowly by means of the\feeding mechanism as a'bove described. All shock o1' vibration which might be produced from the upward strokes of the plunger 6 is absorbed by the spring 11', the block lO on which said spring abuts moving longitudinally in the slot 9 to elfect this end.

A. concrete drill of the construction set forth is compactA and neat in appearance and efficient in its operation.

While I have illustrated and described the v preferred form of construction vfor carryingmy invention into effect, this is capable -of variation and. modification without departing from the spirit of the invention. I therefore do not wish to be limited to the: precise details of construction set forth but! desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having-'described my invention what I claim as new and desire to secure by Letters Patent is: v 1. In a device Vof the class described, a barrel, a tool holder mounted for reciprocation in said barrel, means for imparting ablbw to said tool holder, ya beveledgear rotatably mounted on the end of said barrel and in splined. engagement with said tool holder, a second beveled gear mounted upon-said barrel butin mesh' with Vthe last mentioned gear, arod mounted for'reciprocation and on said barrel and-'operated synchronously with said blow imparting--means,.j and a ratchet connection betwee'n said second bev? eled gear and' the adj cent end vof saidjrod, substantiall asdescribedej- Q..n'a eve of theclas's described, a

www?,

barre, :IL-beveled gem." ,at thev end of said. barrel provided with e hub having a pe- ;phera groove, pair of semicircular bands secure l t he end of. seid bel-rel and each proyded fb im 'naurned Heilige engaging inf said g'oove, a tool holder mounted fof eoproea'ton in -he end of seid barrel and extendmg through sald gear, a spme connectlon between sind gem" and sind too holder, means for iniermttently turning se gem, substantially as described..

En testimony whereof have signed' my neme to this specification in the presence of two subscribing Witnesses. v

FREEERICK J. STENB CH., tneeses ARTHUR A. ULSON, Jos/HUA R, H, Ferre. 

